This invention is directed to a method and apparatus for cleaning and removing contaminants from a pipeline while containing and preventing the contaminants from spilling or leaking into the environment. The method and apparatus effectively removes PCBs, contaminants and debris from gas transmission pipelines so that the level of polychlorinated biphenyls (PCBs) in the pipeline is less than ten (10) micrograms per one hundred (100) square centimeters throughout the pipeline. The invention employs a cleaning solution for cleaning and removing PCBs, contaminants and other debris from gas transmission pipelines. More particularly, the method and apparatus of the invention provides a continuous process for removing PCBs, contaminants and other debris from a gas transmission pipeline while reusing filtered cleaning solution. This is accomplished by recirculating the solution back into the gas transmission pipeline for further removal of additional PCBs, contaminants and other debris that may still be present in the gas transmission pipeline being treated. The present invention implements a novel. coupling system to improve the process of cleaning transmission gas pipelines so that dangerous PCBs and other contaminants are recovered in a closed loop without spillage or leakage.
Apparatus and methods for cleaning debris and contaminants from gas transmission pipelines are known. However, these methods and apparatus present several problems. There is a long felt need for a more effective method and apparatus for cleaning gas transmission pipelines so that they are safer for the environment.
U.S. Pat. No. 1,328,726 to Dezendorf discloses a process for cleaning service pipes by injecting a wet charge and hot, dry charges into a pipeline to be treated. However, the invention is problematic for several reasons. The invention does not disclose the reuse of cleaning solution, nor does it disclose a coupling system for preventing loss or spillage of of contaminants recovered from a pipeline. Pipelines contain contaminants that are dangerous to the environment. There is a long felt need for apparatus and method that operates as a closed environment to prevent spillage or leakage of dangerous contaminants in the process of cleaning pipelines. The present invention solves this long felt need.
U.S. Pat. No. 3,600,225 to Parmelee discloses a method for cleaning sewers by delivering jets of water from a self-propelled nozzle to the inside of a pipe to be cleaned. The invention also discloses a method for recovering the water from the sewer, cleaning the water, and reusing it to clean the sewer. However, the apparatus used in the method of cleaning sewers is problematic. The invention does not disclose a coupling system for preventing loss or spillage of of contaminants recovered from a pipeline. Furthermore, the means for recovering water from the sewer is not coupled to the means for injecting water into the sewer. The invention relies solely on one device for recovering contaminated solution. As a result, maximum contaminated water recovery is not accomplished by the apparatus and method. A coupling system would ensure maximization of water recovery. There is a long felt need for a coupling system in a conduit cleaning system for maximization of recovery of cleaning solution. Furthermore, there is a long felt need for augmenting a contaminated solution recovery means with additional recovery means, such as water pressure, for further maximization of recovery of contaminated solutions. The present invention solves these long felt needs.
U.S. Patent to 4,995,914 to Teter discloses a process for removing hazardous or toxic particulate materials from structures by directing jets of a fluid into an intake tube in the direction of air flow toward a separator chamber causing the particulates, including PCBs, to move along the intake tube to the separator chamber. This method, however, does not recycle cleaning solution for further use. Rather, it recycles air. This method can be quite costly and inefficient. The Teter invention attempts to minimize leakage of contaminants during removal by applying negative pressure to the apparatus. The Teter invention is problematic because xe2x80x9ca small xe2x80x98leakxe2x80x99 may existxe2x80x9d in the application of this method and apparatus.
Other methods and apparatus for cleaning pipes and pipelines are also known. For example, U.S. Pat. No. 2,356,254 to Lehmann, Jr., et al. discloses a method for removing accumulated solid matter from pipelines by injecting a treating agent into the pipelines.
U.S. Pat. No. 3,010,853 to Eliott discloses a method for cleaning. pipes by circulating a cleaning solution under pressure through the pipes. This invention does not disclose a system for recovering the contaminated cleaning solution. This invention relies on a pump to deliver pressure through the pipe. The pressure may be sufficient to return the contaminated solution for some pipes, however, the apparatus may be incapable of recovering the solution for pipes of considerable lengths. Specifically, a recovery device, such as a vacuum, is desirable.
The Elliot invention is used to remove contaminants from the cleaning solution for reuse. However, the process for removing contaminants from the cleaning solution is problematic. Specifically, this patent discloses a chemical reaction for cleaning the contaminated solution. The chemical reaction may not be effective in removing other types of contaminants.
U.S. Pat. No. 3,084,076 to Loucks, et.al. discloses a method for cleaning the interior of pipes by injecting a cleaning material into a pipeline in a substantially vaporous state.
U.S. Pat. No. 4,206,313 to Cavoretto discloses a nozzle for cleaning the interior wall of a pipe.
U.S. Pat. No. 4,549,966 to Beall discloses a method for removing contaminants, such as PCBs, from an aqueous composition by bringing the composition into contact with an organo-clay compound.
U.S. Pat. No. 5,296,039 to Cooper discloses a method for inserting compressible pigs into a pipeline.
U.S. Pat. No. 5,737,709 to Getty, et al. discloses a method for removing explosive agents from the interior of explosive, agent-filled bodies by using high pressure fluid jets.
While these known apparatus and methods for pipelines and other structures are of interest, they do not address the particular need to remove or decrease the level of PCBs in gas transmission pipelines so that they will be safer for the environment.
The method and apparatus of the present invention is effective method and apparatus that operates as a closed environment to prevent spillage or leakage of dangerous contaminants in the process of removing contaminants from pipelines. Particularly, the present invention is effective removing contaminants, including PCBs and other debris, from gas transmission pipelines so that the level of PCBs in the pipeline is less than ten (10) micrograms per one hundred (100) square centimeters throughout the pipeline.
In general, the apparatus of the invention effectively cleans and removes contaminants from a pipeline while containing and preventing the contaminants from spilling or leaking into the environment during the removal. The apparatus comprises: connecting means for forming a closed loop with the pipeline for continuous cleaning of the pipeline; means for placing a cleaning medium into said closed loop; pumping means for delivering said cleaning medium through said closed loop and the pipeline; and recovering means for recouping the contaminants and cleaning medium from the pipeline so that the contaminants and said cleaning medium are prevented from spilling or leaking into the environment.
The main object of the present invention is to provide a method and apparatus that operates as a closed environment to prevent spillage or leakage of dangerous contaminants in the process of cleaning pipelines.
Another object of the present invention is to provide a method and apparatus that effectively cleans gas transmission pipelines so that the level of PCBs in the pipeline is less than ten (10) micrograms per one hundred (100) square centimeters throughout the pipe.
Another object of the present invention is to produce a method and apparatus that provides a new coupling system in a pipeline cleaning system that improves and maximizes recovery of cleaning solution.
Another object of the present invention is to provided a method and apparatus that improves the recovery of pipeline cleaning solution by combining multiple means for recovering the solution.
Additional objects and advantages will become apparent from the foregoing description.